Re: [Linux-Xtensa] Re: xtensa port maintenance

[Chris Zankel <chris@zankel.net>]

Hi Vadim,

On 08/06/2012 11:00 PM, Vadim Malenboim wrote:
> Hi All,
>
> I've beed dealing with the xtensa port for couple of months and I'd 
> like to contribute / help as much as possible.
>
> I have an ML605 Xilinx Evaluation Board and already succeeded running 
> the clean-stable version from xtensa-linux on it.
>
> I propose doing the testing on this board and any other tasks / issues 
> you think I can help, I'd be glad to.

Excellent!! I'm looking forward to your help.

-Chris

>
> Vadim.
>
> On Tue, Aug 7, 2012 at 8:40 AM, Chris Zankel <chris@zankel.net 
> <mailto:chris@zankel.net>> wrote:
>
>     Hi Max,
>
>
>     On 08/06/2012 04:38 PM, Max Filippov wrote:
>
>         AFAIK xtensa linux port is currently in bad shape: it doesn't
>         work in the
>         mainline, it fails to build in the linux-next. The latest
>         working kernels for
>         xtensa are 2.6.29...31 trees hosted at the
>         git.linux-xtensa.org <http://git.linux-xtensa.org>.
>
>     I wouldn't say it's in bad shape, I just built an vmlinux image
>     from the latest tree (3.6.0-rc1), but it might not be very stable.
>     One of the major issues is not really the kernel but  there's
>     actually no way to build a fairly recent version of the toolchain.
>     I have been using a somewhat more recent buildroot version than
>     what is on xtensa-linux.org <http://xtensa-linux.org>, but even
>     that version of buildroot is rather old now and needed a few patches.
>
>     The tree on linux-xtensa.org <http://linux-xtensa.org> has quite
>     diverted from mainline now. Pete has done a great job maintaining
>     those kernel versions, fixing a lot of bugs, and adding a ton of
>     new additional features, but it will take quite some effort to
>     merge them with the latest kernel.
>
>
>         I have a goal to make xtensa arch in the linux mainline usable.
>
>     Awesome!! Every help is very much appreciated.
>
>
>         Currently I have a number of patches on top of Linus' tree
>         that allow to build
>         working allnoconfig, defconfig and allmodconfig kernels for
>         ISS machine with
>         dc232b and fsf core variants [1]. For the next several weeks
>         I'm planning to
>
>     You might expect that I'm more than curious to see those changes :-)
>
>
>
>         forward-port patches accumulated in linux-xtensa.org
>         <http://linux-xtensa.org> git trees and make the
>         resulting kernels rock-solid. I'd like to restore xtensa
>         participation in the
>         linux-next. Further (currently undetailed) plans are to bring
>         modern Linux
>         features to the xtensa port, e.g. device trees.
>
>     That would be great. Might I also add that we'd need to have a
>     working toolchain and bootable image. For me, buildroot seems to
>     be the quickest route here. That would also require possibly
>     adding patches to the toolchain and uClibc that are currently
>     missing. There's also the bootloader, etc.
>
>
>         I have a couple of questions regarding the path of
>         xtensa-specific patches
>         upstream:
>              - which git tree should they be targeted for? Should I
>         set up a tree for
>                pull requests, or will patches be picked up into some
>         existing tree?
>                (Looks like Linus' tree is the right target. AFAIK
>         previously xtensa
>                patches went mostly through akpm tree).
>
>     Yes, Andrew has been very helpful stepping in and adding those
>     patches. Most if not all of those patches were fixes because of
>     generic kernel changes and not major fixes or changes to the core
>     of the Xtensa port.
>
>     Ideally, it would be great if you could create a git tree (I saw
>     you already have a version on github already?) that would allow us
>     to look over those patches. The goal should be to have a system to
>     build toolchain, bootable image, and kernel, so we can run some
>     regression tests on either the simulator (qemu) or an actual
>     board. Once we have a regression test system in place, we can then
>     add more features and funnel those patches either through me or
>     more directly..
>
>     What do you think?
>
>     If you already have such a system in place, it would be great if
>     you could send me some instructions to recreate it locally. We can
>     give you also access to the wiki to add any information there.
>
>
>              - which mailing lists should they go to?
>                (I guess that besides linux-xtensa@linux-xtensa.org
>         <mailto:linux-xtensa@linux-xtensa.org> list they should go
>                to linux-kernel@vger.kernel.org
>         <mailto:linux-kernel@vger.kernel.org> for general review.
>         Anything else?)
>
>     For now, I would really appreciate if you could hold off sending
>     any major patch to the linux-kernel mailing list until we had a
>     chance to look over them unless it's some generic patch (fixing an
>     issue because of an API change to the kernel, etc.)
>
>     Andrew is currently adding all Xtensa patches sent to that list,
>     and I would hate having to irritate him having to ask to remove or
>     change patches, etc.
>
>
>         Should you wonder what I am:
>         I am a member of St.Petersburg Open Source and Linux Lab [2].
>         My previous contributions to Linux are related to p54spi
>         wireless driver.
>         I'm also a developer and maintainer of the target-xtensa QEMU
>         port [3].
>
>     That's so great!! I didn't know there was a QEMU port for Xtensa.
>
>     Bottom line, I hope you agree with me that the kernel, although
>     the most fun part, is only one piece of the puzzle, and we also
>     need a running system. If you already have that in place, we can
>     jump to the kernel fairly quickly.
>
>     Thanks,
>     -Chris
>
>
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>
>
>
>
> -- 
> *Vadim Malenboim.*
>       Low Level Software Engineer.
>
>       Cellular : +972(544)925862
>       E-Mail   : vadim@tangotec.com <mailto:vadim@tangotec.com>
>       WEB     : www.tangotec.com <http://www.tangotec.com>
>
>